1. Field of the Invention
The present invention relates to novel cyclopropane derivatives having anti-viral activity especially effective against varicella-zoster viruses and herpes simplex viruses, to anti-viral compositions containing the same, and to methods of treating patients having varicella-zoster virus or herpes simplex virus with the same.
2. Discussion of the Background
Varicella-zoster viruses cause varicella in infants with high fever and cause zoster in adults with much pain such as neuralgia, etc. Some anti-viral agents such as acyclovir can be used to treat these viruses, but are not always satisfactory in view of their pharmaceutical potency and unfavorable side-effect (see Am. J. Med., 85, (Suppl. 2A), 116-122 (1988), U.S. Pat. No. 4,386,076, JP-A5/78357).